New submitter kevmeister writes "Today T-Mobile decided that unlimited data plans are a good thing after all. Over a year after discontinuation, T-Mobile announced that unlimited data is coming back. 'T-Mobile said the new unlimited data plan will cost $20 a month when added to a Value voice and text plan, and $30 a month when added to a Classic voice and text plan. ... Among its top U.S. network counterparts, only Sprint offers a similar deal, and it costs about $110 a month. But Sprint offers the iPhone; T-Mobile does not. One of the new T-Mobile plan's flaws, though, is that it cannot be used for tethering -- that is, connecting multiple devices to the Internet. MetroPCS, considered the fifth-largest carrier in the U.S., made a big announcement of its own Tuesday, saying it would begin offering an unlimited everything promotional plan for $55 a month for a limited time.'"